Methods for treatment of varices and general ligation methods have long been known in the art. This has long been so for both for human and non-human tissues.
Esophageal varices are enlarged esophageal veins. These frequently complicate chronic liver disease. Esophageal varices may rupture and bleed, potentially leading to death. Ligation of the varices can be performed to treat acutely bleeding varices. Ligation can also be performed preventatively to destroy the varices before they start to bleed. During the process of ligation, varices are suctioned into a hollow space of the ligator and bands are released over the tissue to strangulate it. Strangulation leads to death of the tissue and subsequent scarring obliterates the varices.
The process of ligation can be further effectuated with an endoscope or other device for accessing or penetrating internal aspects of a human, an animal, a fish, or other entity. Endoscopes generally consist of a rigid or flexible tube, a light delivery system, a lens system to transmit images from the object being viewed to the viewer, and an additional channel coupled to the rigid or flexible tube to allow entry of medical instruments.
Currently used variceal ligators manufactured by Wilson Cook and Boston Scientific, use string with attached beads to pull the rubber band off the cylinder that is attached to the tip of the endoscope. A string is pulled via the working channel of the endoscope and via an inner opened part of the cylinder. The string is then split into two parts (two strings) to which beads are attached. These two strings are then placed over the opposite side of the cylinder. Rubber bands are then placed over the strings in a way that each band is separated by a single bead on both sides of the cylinder. When the string is pulled, beads pull rubber bands separately over the edge of the front part of the cylinder and ligate the tissue suctioned in the cylinder. Pulling of the string is performed by a mechanical device attached to the hand of the scope. The mechanical device consists of a knob to which the string is attached. When the knob is rotated by an operator, the string wraps around its central part thus pulling the string and by shortening it, releases the band from the attached cylinder to the tip of the endoscope. As a result, the rubber bands and beads of these variceal ligators cause the outer surface of the cylinder that is to be inserted into the body to be course, thus making it more difficult to insert the ligator into smaller orifices. Furthermore, these devices are not designed for reloading bands.
Other prior art devices include a single band device. These devices allow release of a single band only off the surface of the inner cylinder being pulled inside the outer cylinder by a simple pull of the string. These devices do not provide releasing of multiple bands.
Another prior art ligator is disclosed in U.S. Pat. No. 7,641,652 to Koe et al (the “Koe reference”). The Koe reference discloses a large ligating device mounted substantially spaced from the end of an endoscope. The Koe device includes a mounting arm and other structure surrounding the penetrating end of the endoscope, and the ligating device is transverse to the endoscope viewing component. The Koe device blocks the operator's view of the material to be ligated, so it renders the ligating process difficult and requires significant operator training to use the device with relative accuracy. The Koe device also is bulky and includes substantial edges, wire (including rotating wire), and other components that make introduction into the esophagus difficult, if not impossible.